Fuel injection apparatus



Sept. l24,V 1946. A." T. BREMsI-:R

' FUEL; INJECTION APPARATUS Y Filed Nov. 13, 1942 a an@ Patented Sept.24, 1946 l A2,408,288 FUEL INJECTION APPARATUS Albert T. Bremser,Sidney,` N. Y., assigner to Bendix Aviation Corporation, New York, N.Y.,

a corporationof Delaware -Application November 13, 1942, Serial'No.465,448-

NT OFFICE'.

17 Claims.

.1 a rIhis invention relates to fuel injection apparatus and moreparticularly to means for controlling and effecting the delivery of fuelunder pressure to the cylinder ofa solid fuel injection engine.

ness of said valve.

position.

stuck in closed position.

ing thereof is effected;

pended claims.

'5 One of the objects of the present invention is Referring to Fig. l,I0 is the' head of a cylto provide a novel fuel injection apparatus ofinder of a solid fuel injection engine whereon is the type wherein aninjection nozzle and a fuel mounted a novel fuel injection apparatusempump are embodied in a unitary structure. 4bodying the presentinvention, said apparatus Another object of the invention is to providea l()v A'being preferably of the typecombining a fuel fuel injectionapparatus having a pressure conpump and a fuel injectionv nozzle in aunitary trolled nozzle valve with novel means for prostructure. Theinjection apparatus, in the yform tecting said apparatus and thev engineon which illustrated, comprises a main barrel or housing the same ismounted in the event of inoperativei I` secured to cylinder head I bysuitable means, such as bolts IIa or a clamp (not shown), so that Afurther object is to provide a fuel injection the lower end thereofextendsinto a recess I2 apparatus having novel means for preventing eX-formed in said cylinder head, A nozzle holder cessive fuel delivery inthe event. the nozzle valve body I3 having an external'shoulder I4formed controlling fuel injection becomes locked in open at the upperend thereof is mounted in the lower end of housing I I and is secured inoperative po- Still another objectA is to provide novel'means sition bya gland nut i5 which screws into said in the above apparatus forpreventing deleterious housing andY cooperates with said shoulder, aeffects other than non-delivery. of fuel when the gasket IB beingpreferably interposed between pressure operated nozzle valve becomeslockedor Said shoulder and said gland nut. The latter iS effective tohold nozzle body I3 in abutting seal- A still further object is toprovide a uniflow ing engagement With the lower face of a disc injector,i. e., aninjeetor having an injection member I-which,` in turn, bearsagainst the lowerl nozzle and fuel pump embodied in e, unitary end 0f@Dumpcyllder I8, and presses a shoulstructure, with novel means foreiecting adjustder ia formed on the latter into engagement ment of thenozzle valve s0 as to coni-,rol the 30 with an internal shoulderv in thebore of housing pressure necessary toeffect fuel delivery from AS areSullkIiOZZle bOdy I3; dSC member l1 the nozzle. A Y and pump cylinderI8 are held against axial Still another object is to provide a fuelvinmovement and in fluid-tight engagement With jed-,ion apparatus havingnovel actual-,lng ,means each other, the latter two elements cooperatingfor controlling. the stroke of the movable pumpin aV manner more fullydescribed hereinafter. ing element of said'apparatus. j Threaded on thelower end of nozzle holder A further Objectis to, provide a fuel pumpembody I3 is a sleeve nut I9 which is provided interbcdying a novelarrangement for controlling the mediate its ends with'an internalshoulder 20 for :dowof fuel therein whereby advantageous ccolsupportingengagement with the flanged upper A Y 40 end 2 l'a, of a nozzle sprayor. atomizing tip 2l, said The above and further objects andnovel fea-vtip having a central'bore' or duct 2lb therein and tures of theinvention will more fully appearfrom a plurality ofM radially extendingorifices 2 Ic adthe following detailed description whenthe same jacentthe lower end thereof. 'The nozzle tip 2i is readin connection with theaccompanying projects through the lower end `of sleeve nui-I9 drawing.vlIt is to be. expressly understood, how-A into the combustion chamberof'theengine cyleverthat.the'drawingV is for the purpose of'illusinderso that vfuel can be sprayed from orifices trationenly and is notintended as a definition of Zic into said chamber. The lower end of saidnut the limits of theA invention, reference' for this fits into thelower endof recess I2, and anexlatter purpose being primarily had totheapternal shoulder 22 formed adjacent said lower Y y a n 50 end seatson agasket 23a which is, in turn, sup- In the drawing, wherein likereference charported by an internal shoulder 2.3.in said recess. actersrefer to like parts throughout the vseveral Removably mounted in nut i9above nozzle tip l 2|isa Valve guide 24i that is centrally bored forFig. 1 is a sectional view, withV parts broken slidably receivingV thestem or piston portion of a away and'parts shown in-elevation, of oneform of (Cl. 10S-41) 2. fuel injection apparatus embodying the presentinvention; and,

Fig. 2 is a fragmentary view of a fuel injection apparatus havingamodied arrangement for controlling fuel delivery to the injectionnozzle.

needle valve 25.. The bore through said guide member terminates at thelower or inner end of the latter in a small orifice 24a which is coaxialwith passage 2lb, and a conical seat 25 is provided adjacent saidorifice for cooperation with the tapered lower end of needle valve 25.The latter is thus effective to control the ow of fuel from member 24into duct 2lb and hence into the engine cylinder. Preferably, the borein guide member 24 is enlarged immediately above valve seat 26 toprovide a fuel pressure chamber 2l through which a reduced portion ofvalve 25 extends. Fuel supplied under pressure to chamber 2l through asuitable passage 28 in member 24 in a manner hereinafter described actsagainst shoulder 29 formed on the valve by the reduction in the diameterthereof, and is thus effective to lift the latter off its seat andpermit the flow of fuel from said chamber through passages 24a, 2 I band 2 lc into the engine cylinder.

Valve is normally held in seated or closed position by novel meansdescribed hereinafter which apply a yielding pressure to the valvethrough a pressure pin or spindle 33 that freely extends through thecentral bore in nozzle body i3. The lower end of spindle or rod 30 ispreferably recessed for freely receiving a pin 3| formed by a reducedportion at the upper end of valve 25, Between the adjacent ends of bodyi3 and valve member 2li there is preferably interposed a washer memberor plate 32 having a central recess therein through which pin 3l ofvalve 25 extends, said washer being adapted to engage the upper end ofthe shank of the valve to limit the upward movement of the latter. Apassage 33 extending from the upper end of body I3 conneots with passage2B in guide member 24 through an orifice 34 in plate 32. The latter maybe readily replaced if it becomes worn by the constant hammering ofvalve 25 thereagainst.

In order to deliver fuel under pressure to chamber 2l and thence to thecombustion chamber, pumping means are provided, the same beingpreferably contained in housing il. As shown, said means comprise aplunger 35 slidably mounted for reciprocation in the bore of cylinder I8so that a pressure chamber is formed at the lower end of said cylinderby said bore walls, said plunger and disc member il. A passage lla indisc il connects the pressure chamber to an annular groove l'ib providedin the lower face of said disc and said groove is adapted to overlap andopen into the upper end of passage 33. One or more radial fuel inletports 35 are provided in the wall of cylinder I8 to connect saidpressure chamber with an annular fuel supply groove 3l formed in theinternal wall of housing il, plunger 35 operating as a slide valve tocontrol the flow of fuel through said ports into cylinder I8 in a mannerwell understood in the art. In order that fuel from a suitable sourcemay be employed in a novel manner to cool the fuel pump, the latter isnovelly constructed with a pair of fuel passages 38 disposed in oppositesides of housing Il to connect with groove 3l. Fuel is admitted from thefuel source through one of said passages and may be discharged from theother so that, by delivering a quantity of fuel to the intake passage ata rate in excess of the amount used :by the engine, a continuouscirculation of fuel may be maintained through said passagesand groove 3lte cool the parts adjoining the latter.

To control the point of fuel by-pass, i. e., the termination of fuelinjection, a by-pass port 39 axially spaced above ports 36 is providedin member I8 for cooperation in a manner well understood in the art,with a helical groove 40 formed in the surface of plunger 35, saidgroove being continuously connected to the pressure chamber of the pumpby suitable passages, such as con nected axial and radial passages 4land 42, respectively. To vary the angular relation between meteringgroove 40 and cut-off or by-pass port 39 and thereby vary the effectivepumping stroke of the piston, suitable means for angularly adjustingplunger 35 are provided and. in the form shown, comprise a sleeve 43loosely surrounding the upper end of cylinder I8 in the enlargedinterior of the upper end of housing ll. Gear teeth 44 are formed on thelower end of sleeve 43 for cooperation with a rack member (not shown) ina manner Well-known in the art. The upper end of sleeve 43 is axiallyslotted at 45 for slidably receiving a cross bar 4G rigidly connected toplunger 35. Sleeve 43 seats on an internal shoulder 4l in housing Il andis held against axial movement relative to cylinder I8 by a ring member48 which engages an external shoulder on said sleeve and is positionedagainst an internal shoulder 49 in housing Il, said ring member beingheld on the latter shoulder by a spring 5i) which constitutes an elementof the plunger reciprocating means. The latter comprises a tappet cup 5iwhich is slidably positioned in the upper end of housing Il forengagement with the head portion of a member 52 operatively connected tocr integrally formed with the upper end of vpiston 35. Downward movementis imparted to the latter by means comprising a rocker arm or tappetlever 53 which is pivotally mounted intermediate the ends thereof on asuitable rocker support 54 fixed to the cylinder head. One end of saidarm bears against the upper end of tappet cup 5! and the other end isconnected by a rod 55 to a cam follower 56, the latter being inoperative engagement with the cam 51 which is adapted to rock said armand actuate plunger 35 in a novel manner to be fully describedhereinafter. The downward movement of said plunger is resisted and theupward movement thereof is effected by spring 50 which has the lower endthereof seated on ring member 48 and the upper end thereof engaging awasher 58', which, in turn, engages a downwardly facing shoulder formed-by the enlarged upper end of member 52 to transmit upward forces toplunger 35.

In the conventional fuel injection nozzle, the binding or locking of thenozzle valve in either .l open or closed position, or the clogging ofthe fuel passages, such as orifices 2|c, may produce serious detrimentaleffects, particularly at highl speed operation, which eectssubstantially diminish the life, efficiency and capacity of the engine.To minimize these deleterious effects to the fullest extent and preventpermanent injury to the engine or fuel injection equipment as a resultthereof, novel means are provided in the above-described injectionapparatus to insure safe operation. The novel safety means includemechanism adapted to relieve the pressure which tends to build up in thepressure chamber when nozzle valve 25 is locked in its closed position.For the latter purpose, the upper end of the bore of nozzle holder bodyI3 is preferably enlarged in diameter and receives the threaded upperend portion 30a of spindle 30 on which is mounted a spring supportingmember 58, the latter having an internally threaded bore 59 whereby itisadjustably screwed on the end of said spindle.

Vchamber to unseat valve member 60. vto effect a fuel by-pass from thepump pressure Vslot 66 to fuel supply groove 31.

lia-toepas "siidably mounted in the upper Tend of the' bore 'the lowersurface of saiddisc to normally close a central port`6I in said disc,said port connecting Withvthe pressure chamber of pumpV I8,y 35. Aspring 62 is compressed between member V5&3 and valve member andnormally maintains Vthe latter in operative engagement with disc I1,

said spring also applying the `downward pressure which yieldablypressesy valve into engagement with seat 26. p

'The diameter of port 6.1 is such that the area of valve member 60,which is subjected through Vsaid port to the fuel pressure inthe pumprpressure chamber, is less'than the effective area of valvev shoulder279 which -is acted upon by the same fuel pressure. rAs a result,'during normal '.operation, valve 25 has a greater totalu-pward forceacting thereon for a given fuel pressure than the pressure on valvemember 6 0 through port 6I so that the former is raised from its seatWhile the latter remains closed position. How.. ever, if valve 25becomes stuck in closed position,

asufcient pressure is builtup -in the vpressure Inorder chamber in thelatter event, one or more flutes or slots 63 are provided in theperiphery of valve member EE which serve to connect the bore of i bodyI3 below said member with port 6I when said valve Amember is in openposition. A radial passage 6d connects said bore to an axially extendingslot 65 in the outer surface of flange I4 and said slot opens at itsupper end through a Accordingly, when valve member 60 is inopenposition, fuel is py-passed from the pressure chamber to the supply lineor sumpy Novel means are provided for effecting adjustment of thecompression of spring 62 to thereby control the fuel pressure necessaryto raise valve 25 to open position. As shown, said means comprise aplurality of shims-61 located in the upper end of bore Y59 of member 58so as to bear against -the end of threadedportion- 36a and thereby limitthe extent to which the-latter can be threaded in said bore, By varyingthe number of shims lutilized in this manner, there is obtained anaccurate control of the compression to which spring 62 is subjected. Itis to'be noted that the pressure of said springen member 58`pre- 'ventsthe latter from unscrewing from portion a and vitiating a satisfactoryadjustment once the same has been attained.

Y In order to guard'against detrimental effects of the locking Vorsticking of Valve 25 in open in broken lines in Fig. 1, ports 36 aswellas port 3.9 are closed and no fuel is admitted to the pres- `top deadycenter position. A vmovement of the pump plunger, the piston' in 56'holds plunger as in the desired stationaryposition. From point btopoint c .of the cam surface,the remainder of the suction or up-strokevof the plunger takes place, ports 36 being opened -duri-ng this portion-of the stroke and remaining open from points cto d when the plunger Yisin During this latter the engine cylinder is in the course ofl itscompression stroke so there will be no danger of fuel being forced intothe cylinder by the small pressure in the fuel supply line. At donthecam the plunger begins its power or down-stroke and reaches bottomdead center position when follower 56 engages lpoint e of the cam. Uponcontinued rotation of cam 51, the plunger moves upward until surface 1-b, is again reached to complete the cycle. As a result of this novelconstruction of cam 51, fuel injection into the engine cylinder can takeplace -only during a predetermined part of the engine piston stroke evenwith the nozzle valve locked in Yopen position, Vso that the combustionchamber of the cylinder cannot be flooded with fuel oil.

In normal operation, when plunger is at ytop dead center position priorto the dovvn or power Y35 is closed. When-plunger 35 moves Ydownward toclose inlet ports 36, the pressure lof the fuel in the pressure chamberis built up after the port closure and isV transmitted to chamber .-21,raising valve 25 and thereby permitting fuel to be yinjected into thecombustion chamber of the engine cylinder through passages 2da, 2lbandr2lc. At

a further point in the down-stroke, metering groove d overlaps port 39to connect the fuel supply line 31,l 3S with the pump pressure throughpassagesl 4I 'and t2 and fuel delivery is cut oif. After bottom deadcenter position is reached the suction stroke begins and continues untilpiston 35 reaches a point at which it closes ports 36 and port 39. Atthis point, plunger 35 comes to a standstill and remainsV stationaryuntil a short time before fuel injection is desired. The upstroke isthen resumed and the plunger completes its travel to top dead centerposition, filling the pump and nozzle pressure chamber with fuel atsupply line pressure.

The pressure at which valve 25 opens to begin fuel injection to thecombustion chamber during the power stroke of plunger'35- is readilypredetermined by adjustment of the number of shims 61 inbore 55. y

If valve 25 becomes locked in closed position, the building up of fuelpressure in the pressure chamber unseats valve member andthe fuel fromthe pump pressure chamber is by--passed to the supply line through port6 I, flutes 63, the bore of body I3, and passages 64, 65 and 66. Ifvalve 25 becomes locked in open position, the delivery of fuel to thecombustion chamber in excessive vsure chamber and, therefore, nonecan oWto the combustion chamber of the engine cylinder. Plunger 35 ismaintained in this position by cam j 51 for a substantial portion of theperiod between fuel injections. To accomplish this, said cam, whichrotates in the direction of the arrow, has a. circular contour for asubstantial part of its peripheral. surface, i. e., betweenpoints a andb, which contour when in engagement With-followerl quantities isprevented by plunger 35 which closes ports 3-6 and 39 for a substantialperiod between'v y fuel injections.

The flow of fuel in the supply system through groove 31 is continuous,the same entering said groove through one passage 38 andv leavingthrough the oppositely disposed passage 38. The amount of excess fuelcirculated in this` manner may be regulated in accordance withthe needfor cooling the apparatus.

A modification of the abovefdescribeduni'ow injection apparatus is shownin Fig. 2, wherein a conventional type cam actuates the plunger andnovel means in the nozzle holder body guard against the deleteriouseffects of the locking of nozzle valve 25 in either open or closedposition. As shown, the apparatus comprises a nozzle holder body 10operatively mounted in the lower end of housing II by means of a glandnut I5, sleeve nut I9 being secured to the lower end of said body andcarrying guide member 2li in which is mounted nozzle valve 25. A washermember 1I is held between the lower end of said body and the upper endof said guide member and has a central recess through which pin 3l ofvalve 25 extends. Body 18 is provided with upper and lower axialrecesses or bores 12 and 13, respectively, which are connected to eachother by a port 14. A passage 15 connects bore 12 with an annular groove16 formed in the lower end of body 10 and said groove communicates witha groove 11 in the upper end of valve guide member 24 by means of one ormore passages 18 in washer member 1I, groove 11 being in turn connectedto the upper end of passage 28. Bore 13 is preferably connected by apassage or series of passages 18 to the upper end of body 10 and,accordingly, opens into fuel supply groove 31.

A delivery valve adapter unit 18 having an external flange 19a formedthereon at the upper end thereof is mounted in the upper portion of bore12 and flange 19a is pressed tightly between a gasket 10a and the lowerend of cylinder I8, said gasket fitting into an annular indentation inthe upper end of body 18. The central bore of said adapter opens intothe pump compression chamber and a retraction type delivery valve 80 isslidably mounted in said adapter bore to control the fuel ow from saidchamber to bore 12. The upper end 85' of said delivery valve is adaptedto engage a conical seat 8l in said adapter bore and a cylindricalportion 88a is formed at the lower end of said valve for fluid-tightengagement with the internal walls of adapter 19. An annular groove 88his provided between the upper end yof portion 88a and axial flutes 88o,said flutes connecting at the upper ends thereof with a chamber 82,which is formed immediately below seat 8l by an enlargement of theadapter bore. A spring' 83 disposed between the bottom wall of bore 12and a shoulder 88d formed on valve 80 yieldably urges the latter upwardand normally maintains said valve in closed position. When a suiiicientpressure is built up in the pressure chamber of the pump I8, 35 to liftsaid valve from seat 8l and withdraw portion 88a from the adapter bore,the pressure chamber is open .to bore 12 and :the fuel pressure thereinis transmitted .to Valve 25 through passages 15, 18' and 28. Thus, evenif valve 25 is locked in open position fuel delivery to the enginecylinder can occur only when the sufficient pressure is built up in thepressure chamber to move delivery valve 80 to open position.

Novel means are also embodied in body 10 for yieldably urging valve 25into engagement with its seat and for preventing any serious detrimentaleffects when said valve becomes stuck or otherwise inadvertently lockedin closed position. In the illustrated embodiment, said means comprise apressure transmitting element 84 disposed in the lower end of bore 13and loosely mounted on the upper end of pin 3l so as to transmitdownward forces to the latter. An upwardly facing shoulder 84a is formedon said element and the lower end of a spring 85 seats on said shoulderand is centered by the shank of said element, said spring being heldunder compression between said shoulder and a Valve mechanism in theupper end of bore 13 so that valve 25 is pressed in the direction of itsseat. Said mechanism comprises a screw member or stud 81 having a flange81a formed at the base of the head thereof for engaging the upper end ofspring 85, said head serving as a centering guide for said spring. Screwmember 81 is threaded into the lower end oi a valve member 88 which isslidably mounted in bore 13 and has a needle valve element 88aintegrally formed with or otherwise rigidly secured to the upper endthereof. The lower end of port 14 is flared to form a conical seat whichcooperates with valve element 88a to normally prevent fuel flow throughsaid port into bore 13. A plurality of axial grooves or flutes 88h areformed in the periphery of valve member 88 to interconnect the upper andlower ends of said bore so Ithat passage 18 communicates with bore 12when valve 88a is open.

The cross-sectional area of port 14 is such that the total effectivefuel pressure acting downwardly on valve 88 is less than the totalpressure acting upwardly on valve 25 so that in normal operation valve88 is always closed and valve 25 is opened periodically in response tothe pressure created by the pump to permit fuel delivery from bore 12 tothe combustion chamber of the engine cylinder. However, in the eventvalve 25 becomes locked in closed position, the pressure in bore 12will, during the effective pumping stroke of the pump plunger, causevalve 88 to open so that fuel is by-passed from said bore through port14 to bore 13 and from the latter bore back to .the fuel supply line viapassage 18.

In order to control the compression of spring and, therefore, the fuelpressure at which valve 25 will be lifted from its seat. a plurality ofwasher-like shims 89 are disposed between the upper face of shoulder 81aand the lower end of member 88. The axial position of screw member 81can be accurately adjusted by varying the number of shims 89 and thusprovides accurate means for regulating the pressure exerted by spring85.

There is thus provided a novel fuel injection apparatus of the uniowtype wherein a fuel pump and a fuel injector are combined in a unitarystructure. The apparatus embodies novel means for insuring .against anypermanent or serious deleterious results in the event the nozzle valveis bound or otherwise locked against movement either in open or closedposition. Novel means are included for preventing excessive fueldelivery to the engine cylinder when the nozzle valve is in openposition as well as novel means for relieving the pressure built up inthe pump compression chamber when the nozzle becomes clogged or thenozzle valve remains closed during operation. There is also provided anovel arrangement whereby the nozzle valve operation can be controlled,i. e., whereby the fuel pressure at which the valve will be lifted fromits seat can be accurately predetermined during assembly of ltheinjector.- Additionally, the novel structure provided includes meanswhereby cooling of the same may be effected in a novel manner. Stillanother novel feature of the pump and nozzle unit provided is thelocation of the by-pass port above the inlet port of the pump to insureagainst any accumulation of air in the pump compression chamber.

Although only two embodiments of the invention have been illustrated anddescribed. it

isV to be expressly understood that the same is not limited thereto.For4 example-,fit will now be` apparent to those skilled in'theart thatother types of delivery valve units may be employed in the embodiment ofFig. 2, that insteadiof `a single spring, separate springs may beemployed for normally maintaining safety valve fill or 88 and `nozzlevalve 25 in closed position, :and that by-pass port 39 may be connectedto any lowv pressure space other than the supplyline 3l, 38. It is to beunderstood also thatthe nozzle safety valves and adjusting mean-s shownin Figs. V1 and 2` for relieving the fuel vpressure in the pumppressure'chambers may bev interchanged. Various other changes mayy alsobe made in the design and arrangement of'parts illustrated with. outdeparting from the spirit and scope of the invention. For a denition ofthe limits ofA the invention, reference is had primarily to the appended claims.

What is claimed is 1. In fuel injection apparatus of the classdescribed, pump means comprising a casing, a cyl-Y inder in said casingandy areciprocating plunger in said cylinder, said cylinder Vhaving portmeans controlled by said plunger and connecting the interior of thecylinder with an annular space between said casing and cylinder, saidspace having an inlet and an outlet independent of said ports wherebyfuel may be circulated therethrough irrespective of the position of saidplunger and said space being the sole connection between said inlet andoutlet when said port means are closed by the plunger.

2. In fuel' injection apparatus, pump means comprising a casing, acylinder in said casing' said cylinder and casing cooperating to form anannular space therebetween having an inlet and an outlet through saidcasing, and a reciprocating element in saidcylinder for controllingcommunication between said space and the interior of said cylinderthrough ports in the walls of said cylinder, said space being annularwhere'-r by fuel may be continuously circulated around said cylinderirrespective of the position of said element and said space being thesole connection between said inlet and outlet when said port means areclosed.

3. In apparatus of the class described, fuel pumping means for aninternal combustion engine, a first valve means responsiveto pressurecreated by said pumping means for controlling the llow of fuel from thepressure chamber of said pumping means into an engine cylinder, a secondvalve means responsive to said pressure for controlling the flow of fuelfrom said pressure chamber to a point outside said cylinder, said firstvalve means being adapted to open in response to a lower pressure thansaid second valve means, and a single resilient means for normallyholding both said valve means in closed position, said first and secondvalve means being in axial alignment with each other and with saidpumping means.

4. In apparatus of the class described, fuel pumping means for aninternal combustion engine, a rst valve'means responsive to pressurecreated by said pumping means for controlling the iiow of fuel from thepressure chamberl of said pumping means into an engine cylinder, asecond valve means responsive to said pressure for controlling the flowof fuel from said pressure chamber to a point outside said cylinder,said first valve means being adapted to openin response to a lowerpressure than saidsecond 10 valvexmeans, and common yieldable meansfornormally holding said rst andi second valve meansin closed position.

5. fuel injection apparatus for internal combustion engines, meansforsubjecting aliquid fuel to pressure for forcing the same into thecylinder'of an. internal combustion engine, a first valvemeans'responsive-to the pressure of said'fuel for controlling `the flowof fuel into said cylinder, a second valve means responsive to thepressure of said fuel for controllingthe low of said fuel 'to aypointfoutside said cylinder, and common means lfor yieldably biasingsaid first and second valve means toward closed position, the effectivearea of said Second valve means acted upon by said fuel pressure beingless than the `corresponding area of said rst'valvemeans when both saidvalve means are in closed position.

6. In apparatus of the class described wherein liquid lfuel is suppliedunder pressure @by a fuel pump, the combination of, a valve responsiveto fuel pressure created by said pump forcentrolling the flow .of fuelthrough an orifice, valve means for relieving the pressure in said pumpwhen said valve fails to open in response toa predetermined maximumpressure, and common resilient means interposed between said valve andvalve, means for normally holding the same in closed position.

,'7. In apparatus of the class described, a fuel pump comprising acylinder having inlet and by-pass ports therein, a plunger in saidcylinder for controlling the flow through said ports, and means forperiodically reciprocating said plunger, said last-named means` beingoperable to cause said plunger to close said ports during at least amajor portion of the interval between the beginning of successive cyclesof operation of said plunger. Y

8; In fuel'injection apparatus for an internal combustion engine, pumpmeans, means con-y nectingr the pressure chamber of said pump means to asource of fuel supply, means connecting said chamber to the cylinder ofan internal combustion engine, said pump means comprising means forcontrolling said first-named connecting means, and means for cyclicallyoperating said controlling means to cut ofi communication between saidchamber and source during at least a major portion of the intervalbetween the beginning of successive cycles of operation` of saidcontrolling means.

9. In fuel injection apparatus, a cylinder, a plunger mounted forreciprocation in said cylinder and defining a pressure chambertherewith, means for supplying liquid fuel to said chamber, vmeans fordelivering fuel from said chamber to a combustion chamber, said lastnamed means including a pressure responsive control valve, and means foractuating said plunger so as to maintain said plunger stationary for asubstantial portion of the duration'of each suction stroke thereof, saidplunger in the stationary position thereof being effective to cut oifcommunication between said rst named means and the pressure chamber.

10. In fuel injection apparatus, fuel pumping means adapted toperiodically apply pressure to a quantity of fuel, means comprising adelivery line from said pumping means to an engine compression chamber,a pressure responsive valve normally maintaining said delivery lineclosed, said valve being moved to open position by the building up offuel pressure in said line, means comprising a by-pass passage forrelieving the pressure in said delivery line, a valve responsive to thepressure of the fuel for controlling the ilofw of fuel through saidpassage, and common resilient means for normally holding both of saidValves in closed position, said second-named valve being moved to openposition only when said first-named valve is closed and a pressure inexcess of that necessary to normally open said first-named valve isbuilt up in said delivery line.

l1. In fuel injection apparatus, a cylinder, a plunger mounted forreciprocaticn in said cylinder and defining a pressure chambertherewith, at least one fuel supply port communicating with saidpressure chamber, a pressure responsive control valve adapted toregulate the fuel discharge from said chamber, and means including a camfor actuating said plunger, said cam main,- taining said plungerstationary for the greater portion of the duration of each completestroke cycle thereof at a point in the suction stroke when said plungercloses said port.

12. In apparatus embodying a fuel pump, means comprising a deliverypassage adaptedto deliver fuel from said pump to a discharge orifice, acontrol valve actuated by the fuel pressure in said passage to open thelatter for fuel discharge, a delivery valve operatively associated withsaid pump to control the fuel delivery to said delivery passage, aby-pass passage connected to said delivery passage at a point betweensaid delivery and control valves, and a by-pass valve normally closingsaid by-pass passage, said last-named valve being moved to open positionby the fuel pressure in said delivery passage when said pressure exceedsthe pressure normally necessary to actuate said control valve to openposition and all of said valves being co-axial with each other and withsaid pump.

lf3. In fuel injection apparatus embodying a fuel pump, means Comprisinga delivery passage adapted to .deliver fuel from said pump to adischarge orifice, a control valve actuated in one direction by the fuelpressure in said passage to open said orifice for fuel discharge, aby-pass passage connected to the pressure Chamber of said pump, aby-pass valve normally closing said bypass passage, said by-pass valvebeing movable in the opposite direction to open position by the fuelpressure in the pump pressure chamber when said pressure is in excess ofthat necessary to move said control valve to open position, and commonresilient means interposed between said valves for normally holding thesame in closed position.

1li. In injection apparatus of the uniow type having a housing andpumping means in said housing including a cylinder and a plunger, a fuelsupply chamber in said housing surrounding said cylinder and adapted tobe connected periodically with the pressure chamber of said pumpingmeans, and means including a pair of passages disposed on opposite sidesof said housing so as to connect with said chamber for continuouslycirculating fuel through said chamber at a rate exceeding that necessaryto feed said pumping means, said chamber being the sole connectionbetween said pair of passages.

15. In apparatus of the class described, a fuel pump comprising acylinder having inlet and by-pass ports therein, a plunger in saidcylinder for controlling the flow through said ports, means forperiodically reciprocating said plunger, said last-named means beingoperable to cause said plunger to close said ports during at least amajor portion of the interval between the beginning of successive cyclesof operation of said plunger, a first valve means responsive to pressurecreated by said pump means for controlling the flow of fuel from thepressure chamber of said pump means into an engine cylinder, and asecond valve means responsive to said pressure for controlling the ow offuel from said pressure chamber to a point outside said engine cylinder,said rst valve means being adapted to open in response to a lowerpressure than said second valve means.

16. In fuel injection apparatus of the class described, a pump casing, apump cylinder in said casing, a reciprocating plunger in said cylinder,a tubular nozzle holder body extending into said pump casing in axialalignment therewith, means for securing said cylinder and nozzle holderbody in said pump casing, an adaptor interposed between said nozzleholder body and said cylinder, a delivery valve operable in said adaptorfor controlling the flow of fuel from the pressure chamber in saidcylinder to said nozzle holder body, means for supplying liquid fuel toa space in said pump casing around said cylinder, means including aby-pass valve in said nozzle holder body for connecting the interior ofsaid nozzle holder body to said space, a control valve for controllingthe flow of fuel through said nozzle holder body to a combustion space,and common resilient means interposed between said by-pass valve andsaid control valve for normally holding the same in closed position.

17. In fuel injection apparatus of the class described, a'fuel pumpcomprising a casing, a cylinder in said casing and a reciprocatingplunger in said cylinder, a nozzle holder body, means for securing saidnozzle holder body and said cylinder in said pump casing in axialalignment with each other, a pair of valves in said nozzle holder bodyadapted to be moved to open position by the fuel pressure created bysaid pump, one of said valves being a control valve adapted to normallycontrol the flow of fuel to a combustion space and the other being aby-pass valve adapted to control the flow of fuel to a region of lowpressure for relieving the fuel pressure in said cylinder and holderbody whenever said control valve fails to open in response to apredetermined maximum pressure, and common resilient means interposedbetween said valves for normally holding the same in closed position.

ALBERT T. BREMSER.

